Many medications are delivered to a patient from an intravenous (IV) bag into which a quantity of a medication is introduced. Sometimes, the medication may be an admixture with a diluent. In some cases, the IV bag contains only the medication and diluent. In other cases, the IV bag may also contain a carrier or other material to be infused into the patient simultaneously with the medication. Medication can also be delivered to a patient using a syringe.
Medication is often supplied in powder form in a medication container or in a vial. A diluent liquid may be supplied for making an admixture with the medication in a separate or diluent container or vial. A pharmacist may mix a certain amount of medication (e.g., which may be in dry form such as a powder) with a particular amount of a diluent according to a prescription. The admixture may then be delivered to a patient.
One function of the pharmacist is to prepare a dispensing container, such as an IV bag or a syringe, that contains a proper amount of diluent and medication according to the prescription for that patient. Some prescriptions (e.g., insulin) may be prepared to suit a large number of certain types of patients (e.g., diabetics). In such cases, a number of similar IV bags containing similar medication can be prepared in a batch, although volumes of each dose may vary, for example. Other prescriptions, such as those involving chemotherapy drugs, may require very accurate and careful control of diluent and medication to satisfy a prescription that is tailored to the needs of an individual patient.
The preparation of a prescription in a syringe or an IV bag may involve, for example, transferring fluids, such as medication or diluent, among vials, syringes, and/or IV bags. IV bags are typically flexible, and may readily change shape as the volume of fluid they contain changes. IV bags, vials, and syringes are commercially available in a range of sizes, shapes, and designs.